A few months ago my desktop started hanging on shutdown/sleep and I had isolated it to only happening after I played a game. Any game, any length of time.
When it started, WoW was all I was playing. Recently I picked up a bunch of games from the Steam sale and I'm having the same issue.
If I use my computer for anything else, I have no problems. I can boot/sleep/shutdown all day long. The first time I open a game, close it, and try to shutdown or sleep, the system hangs and I have to force it to shutdown.
Hardware is AMD Phenom2 email@example.com, sapphire radeon 5870, 16gb ram, crucial m4 ssd. The ssd is a recent addition. When it originally started, I was using a wd caviar black 1tb as my main hd. So I have done a fresh install since it started. I've made sure drivers were up-to-date. Even tried using older drivers to no avail.
I've tried reading through Event Viewer, but don't see anything useful with a timestamp close to when I would attempt to shutdown.